package com.example.downloadingimageandpuingrid;

import android.support.v7.app.ActionBarActivity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.os.Bundle;
import android.widget.ImageView;

public class MainActivity extends ActionBarActivity {

    public String url;
    public Byte [] imageBytes;
    public ImageView imageView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.gallery_item);
        imageView = (ImageView) findViewById(R.layout.gallery_item);
        url = "http://animalia-life.com/odin/Cat/cat5.html";
        new FetchItemsTask().execute();
    }


    private class FetchItemsTask extends AsyncTask<Void,Void, byte[] > {
        @Override
        protected byte[] doInBackground(Void... params) {
            return new UrlDownload().getUrlBytes(url);
        }

        @Override
        protected void onPostExecute(byte[] imageBytes) {
            final Bitmap bitmap = BitmapFactory
                    .decodeByteArray(imageBytes, 0, imageBytes.length);
            imageView.setImageBitmap(bitmap);

        }
    }
}

package com.example.downloadingimageandpuingrid;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

import android.util.Log;

public class UrlDownload {
    byte[] getUrlBytes(String urlSpec)
    {
        try{
        return download(urlSpec);
        } catch(Exception e){
            //e.printStackTrace();
            Log.e("UrlDownload", "error downloading");
            byte[] empety = {};
            return empety;
        }

    }

    public byte[] download (String urlSpec) throws IOException
    {
        URL url = new URL(urlSpec);
        HttpURLConnection connection = (HttpURLConnection)url.openConnection();
        try {
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            InputStream in = connection.getInputStream();
            if (connection.getResponseCode() != HttpURLConnection.HTTP_OK)
            {
                return null;
            }
            int bytesRead = 0;
            byte[] buffer = new byte[1024];
            while ((bytesRead = in.read(buffer)) > 0)
            {
                out.write(buffer, 0, bytesRead);
            }
            out.close();
            return out.toByteArray();
        }
        finally {
        connection.disconnect();
        }
    }
}

<?xml version="1.0" encoding="utf-8"?>
<ImageView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/gallery_item_imageView"
    android:layout_width="match_parent"
    android:layout_height="120dp"
    android:layout_gravity="center"
    android:scaleType="centerCrop" >

</ImageView>